(1) Field of the Invention
An improved kind of household clothes drying machine which is provided with an auxiliary condenser in order to reduce the energy consumption and the time required to perform a normal drying cycle is here described.
(2) Description of Related Art
The known condenser drying machines are generally provided with means for removing the moisture from the drying air comprising a condenser through which there is conveyed, further to the flow of the drying air itself, a second flow of cooling air, occurring of course separately from said flow of drying air, which is taken in from the outside ambient and appropriately delivered to flow through and, as a result, cool down said condenser.
Although reference to an autonomous, i.e. self-standing clothes drying machine will be made throughout the following description, it shall be appreciated that what is set forth below may similarly be applied to and, therefore, be suitable for combined clothes washing and drying machines.
The machines, which the present invention refers to, are generally known in the art. They have on the other hand been described, along with a detailed discussion of a technical nature on the advantages and the drawbacks of a number of different variations in the design and general embodiment thereof, in the European Patent Application no. 03028410.3 and no. 04101800.3, filed by this same Applicant to which reference should therefore be made for reasons of greater convenience and brevity of this description.
The present invention preferably applies to clothes drying machines which, further to a condenser, are also provided with:
two distinct fans for blowing the drying air and the condenser cooling air, respectively,
a single motor adapted to drive both said fans at the same time,
said motor being adapted to be controlled so as to selectively rotate in the two opposite directions.
However, it will be readily appreciated that the present invention may be equally applied to condenser-type clothes drying machines of a traditional kind, i.e. provided with a regular condenser, but lacking the other features as indicated above.
Largely known in the art are clothes drying machines that operate either by condensing a flow of hot air, which is first blown into the clothes-holding drum and, while circulating therethrough, removes moisture from the same clothes, or by exhausting said flow of hot moisture-laden air directly outside.
Upon having been blown into the clothes-holding drum, the hot air causes the moisture contained in the clothes to evaporate, thereby becoming almost saturated, or even fully saturated, therewith. This hot, moisture-laden air is then pushed further by said fan, thereby creating a continuous flow that is eventually sent into an appropriate condensation arrangement, which is usually constituted by a heat-exchanger flown through—along the so called “hot” path—by said flow of hot moisture-laden air and—along the so-called “cold” path—by a substantially continuous flow of fresh air that is taken in from the outside ambient and is exhausted again into the outside ambient upon having so flown through said heat-exchanger. Usually, even said flow of fresh air in the so-called “cold” path is activated and maintained by a fan, which is driven in a traditional manner by a respective electric motor.
Largely known in the art is also the fact that, during the initial phase of the drying process, no need would be actually felt for the drying air to be caused to undergo such moisture removal process by letting it pass through the condenser, since it in fact undergoes a certain extent of condensation by itself owing to a still quite low temperature prevailing in the machine. Moreover, during the initial phase of the drying process, the need arises for both the clothes to be dried and the drying air itself to be heated up to the steady-state temperature thereof, so that, in this initial period, condensation taking place at the condenser would anyway be quite limited and, therefore, would make a cooling down of the drying air plainly useless, if not even detrimental.
However the solutions of the prior art all show the common feature that the whole flow of drying air is always made to pass across the condenser or, if existing, the two stage condenser of the latter cited prior art.
This means that this flow of moisture-laden air flow is continuously returned to the drum; when, particularly in the initial phase of the drying cycle, said “hot” air is quite humid, a certain amount of said moisture is unavoidably returned into the drum, independently of the efficiency of the condensing process.
Therefore the presence of moisture that is being circulated from the drum to the condenser, and from it back to the drum, without being effectively condensed, causes an increase of the time length of the drying cycle and an increase of the energy consumption.
It would therefore be desirable, and it is actually a main purpose of the present invention, to provide a condenser-type clothes drying machine, which is capable of ensuring a standard level drying performance, and is however capable of eliminating the above-cited drawbacks of recirculation of the moisture-laden air and the resulting unwanted increase of energy consumption.
According to the present invention, this aim is reached, along with further ones that will be apparent from the following description, in a condenser-type clothes drying machine incorporating the features as recited in the appended claims.